Improving The Quality of Tofu Waste as A Source of Feed Through Fermentation Using the Bacillus amyloliquefaciens Culture

High levels of crude fiber contained in tofu waste become a limiting factor for its use as a source of feed. The purpose of this research is to improve the quality of tofu waste as a source of feed through the ensilage  process using the Bacillus amyloliquefaciens bacteria. The design used was the Factorial Complete Random Design with two treatments, i.e. the Bacillus amyloliquefaciens concentration and fermentation time. This research used three Bacillus amyloliquefaciens concentrations, i.e. 5 %, 10 %, and 15 %, and six fermentation times, i.e. 2 days, 3 days, 4 days, 5 days, 6 days, and 7 days. Based on the analysis of variance, the treatment of Bacillus amyloliquefaciens concentration and fermentation time and their interaction had an effect on the level of crude fiber and the total silage acid of tofu waste (P<0.01), but did not have an effect on its water level (P>0.05). The greater the dose of Bacillus amyloliquefaciens inoculated on the tofu waste, the smaller the average value of its crude fiber; contrary to the total lactic acid produced. The best treatment was obtained at doses of Bacillus amyloliquefaciens of 15 % fermented for 5 days with an average of crude fiber level of 17.3 % and total acid average of 0.87 %, which means they meet the requirements of SNI (Indonesian National Standard) for the ideal total acid criteria, i.e. 0.5-2.0 %. A decline in the level of silage crude fiber of tofu waste reached 44 % compared to tofu waste raw material. Based on the organoleptic test, the silage resulting from the fermentation of Bacillus amyloliquefaciens with a 15 % dose had the best aroma, color and texture compared to doses of 5 % and 10 %.